无码高清视频|成人自拍视频|欧美成人午夜无码A片秀色直播|草美女视频网站|美女被操网站在线观看

單項(xiàng)選擇題

Regulations require that tank vessels handling grade B liquids shall have their cargo pumps separated from all sources of vapor ignition by().

A.cofferdams
B.empty cargo spaces
C.gas tight bulkheads
D.areas equipped with power ventilation

微信掃碼免費(fèi)搜題